This renewal application seeks support for continuation of a unique and timely research training program in Cellular and Molecular Microbiology conducted by an interdisciplinary group of faculty investigators at Vanderbilt University (VU) and Meharry Medical College (MMC). These investigators represent the coalescing disciplines of microbial pathogenesis and cell biology which evolve into the growing field of cellular microbiology. The Program offers trainees with research opportunities for new discoveries in the study of the pathogen-host interactions relevant to biodefense and other microbes that cause human diseases, including Severe Acute Respiratory Syndrome (SARS). The training faculty at VU and MMC has demonstrated a highly effective commitment to 13 predoctoral students supported by this Program. The innovative features of this program are vested in state-of-the-science cell biology approaches as applied to the study of organisms important for human pathogenesis in the following areas: (i) Host-Cell Interaction with Potential Bioweapon Agents and Development of Countermeasures;(ii) Virus-Cell Interactions;(iii) Microbial Adhesion to Cellular Receptors;(iv) Microbial Cues for Cytoskeleton, Cytokinesis and Cell Cycle;(v) Endosomal-Lysosomal Pathway of Microbial Internalization and Processing;(vi) Signal Transduction and Gene Transcription Evoked by Pathogens;(vii) Nuclear Import and Export;(viii) RNA and DNA Binding Proteins in Pathogen-Host Interaction;(ix) ER and Golgi Pathways for Microbial Peptides, Glycolipids, and Glycoproteins;and (x) Mitochondria and Microbial Strategy for Survival. This well-defined Program recruits predoctoral trainees with explicit interests in cellular microbiology of pathogen-host interactions from a pool of graduate and MD/PhD students who matriculated to VU and MMC and have indicated microbiology, virology, immunology, and/or molecular cell biology as their area(s) of interest. These students are offered the Program's flagship course, "Cellular Microbiology of the Pathogen-Host Interaction." The competing application also proposes inclusion of select summer undergraduate trainees, with special emphasis on underrepresented minorities, who seek a career in the biomedical sciences. The Program is based on a stringent selection and monitoring by the Steering Committee which promotes vigorous mentorship and scientific interactions between participating laboratories and early career counseling. The Program's overall mission is to interface trainees with a highly interactive group of VU/MMC faculty and to foster the career development of new pioneers in the field of cellular microbiology of the pathogen-host interactions.